Bi-weekly water change - issues now?

[Cermet]

Well, was getting ready for my bi-weekly water change on the discus tanks and suddenly realized that I will add far more nitrates to the tank than I could remove if I do this water change.

Thanks to all the plants, the tanks are both under 2 ppm nitrate but the issue for me is that the tap water is 5 ppm nitrate. I still do my daily after dinner (for the discus dinner) tank vacuum (removes 10%) but now that both my phosphates (under 1 ppm) and nitrates are dropping so low, I now wonder if it makes sense to do a 50% WC today (I'll still stick to my other WC of 80/90%.)

While an RO would solve the tap water issue, it would raise the mineral issue and so makeup 'mineralize' water might very well return more nitrates than the fish are producing.

Not clear on what is best now - maybe the tap water will clear in a few months but until it does, my plants are removing nitrates and phosphates faster than my WC ever could - puzzled on what is the best procedure to now follow ... any ideas? :sconfused:

[pjaldave]

Is discus that sensitive even to 5ppm nitrates? Sorry, I just don't know if they are, because usually people is fine with 5ppm.

Search for some nitrate remover like De'nitrate by SeaChem, though they need relatively slower flow rate to work.

[Cliff]

I’m not too sure what your local water supply is like, but in a lot of places that I have lived there was a slight increase in nitrates and phosphates just after the spring melt. Right now where I live the nitrates in our water supply increase from around 1 ppm to just over 5ppm in the late spring, usually starting mid/late April and ending by May/June. It might be best to do more frequent and smaller water changes for a while to see if the levels in your water supply change over the next few weeks.

Before you had added the plants to your set-up, did you ever have algae problems ?

[Cermet]

[QUOTE=pjaldave] (are) discus that sensitive even to 5ppm nitrates? Sorry, I just don't know if they are, because usually people is fine with 5ppm.
QUOTE]

Yes, discus do not do well in nitrates of 5 ppm. They want as close to 0 ppm nitrate as possible - absoultly required if interested in breeding ... I'm currently not, however.

My main concern about my frequent water changes is that since my 'replacement' water is above this 5 ppm level then I am causing more harm than good with WC's. That is, the tank constantly remains below 1 ppm nitrate (thanks to the plants) without or with WC's. So essentially, my water changes are putting more nitrates in and buying me nothing. Since I do a min. of 10% a day and two very large bi-weekly changes I’m adding nitrates even faster than the fish/filtering system produces this chemical waste.

Now, I'm not too worried about trace minerals not being added back (used by fish/plants) since I will remain doing the weekend 80 - 90% WC. All the other WC’s now concern me - can't see any use for them if they make my water worse, not better.

Chemical treatment or bio-reactors ($$$ and not sure how good they are) are an option but again, not sure what they buy me if the WC isn't needed and I am replacing missing minerals - I mean my tank remains nearly pristine without water changes thanks to the filters and plants.

Worried I'm missing something here ...
:hal:

[Cliff]

I've only read about this, but have you looked into using RO water and adding back all the required elements with a water additive meant for FW put through a RO unit. That way you get stable FW without any nitrates or phosphates of any kind.

I once talked to a discus owner when I lived in Toronto who had to do that for his discus. At the time I never did understand why, but the water supply (at least were I lived) had just over 5ppm of nitrite and a very slight amount of ammoina

I do not have any first hand experience in this. It's only something that I read about once.

[Cermet]

Before you had added the plants to your set-up, did you ever have algae problems ?

Oh boy, yes. Even with my water changes and before I had any nitrates in the tap. Now, I am doing far better and I am sure this has to do with my under 1 ppm phosphate readings in the tank (before, even though the tap had zero, my phosphates measured 2 - 3 ppm no mater my water changes.) Very happy to see that monster under control now ... :19:

By the way, I'm hoping this Nitrate issue in the tap water is just a temporary issue and clears up. Still, I may give up all the large water changes and like you suggest, stick to a number of small ones. Can't see any harm if my nitrates remain under 1 ppm ... :hmm3grin2orange:

[3dees]

5ppm of nitrates are not going to harm any fish including discus. unless you have a tank full of plants, or doing large wc's every day, it's almost impossible to keep your nitrates at 0. discus are not as fragile as some would have you believe.

[Cermet]

I've only read about this, but have you looked into using RO water and adding back all the required elements with a water additive meant for FW put through a RO unit. That way you get stable FW without any nitrates or phosphates of any kind.


I wouldn't consider RO because I'd have a bear of a time re-adding the missing minerals (my tap water is very soft, already.) using chemicals sounds scary because I'd be operating in the dark - no idea what really was missing or had too much of ... .

However, I have looked at and wonder if the bio-reactors that they sell for both SW and fresh that remove nitrates with bacteria (not sure now these work with oxygen in the water) might be worth while if the nitrates don't clear this summer.

Any experience with these?

[Cliff]

I've never used them in FW, only SW.

[Cermet]

5ppm of nitrates are not going to harm any fish including discus. unless you have a tank full of plants, or doing large wc's every day, it's almost impossible to keep your nitrates at 0. discus are not as fragile as some would have you believe.

I agree that they can handle 5 ppm but they do not breed in it. Most discus keepers really prefer that they stay in water close to 0 ppm nitrates, as possible. I've always had that, until lately ...

[Cermet]

I've never used them in FW, only SW.

Do you, by any chance, understand how they can use bacteria to do this (that I know they do use bacteria, not chemicals, since they say this up front) with oxygen in the water? I was under the impression that such bacteria does not tolerate high levels of oxygen. Still, if they really work, doesn't matter one way or the other - only that this isn't snake oil ... .

[Cermet]

unless you have a tank full of plants.

Missed this issue completely - excellent point - having nitrate levels so low may really hurt the plants ... if I drop too low on nitrate input, the plants may suffer and die back - leading to nitrates climbing AND my poor plants going down (followed by climbing phosphates and algae.)

Ugh - didn't consider that issue at all - thanks!:22:

[Cliff]

Do you, by any chance, understand how they can use bacteria to do this (that I know they do use bacteria, not chemicals, since they say this up front) with oxygen in the water? I was under the impression that such bacteria does not tolerate high levels of oxygen. Still, if they really work, doesn't matter one way or the other - only that this isn't snake oil ... .

The reactor that I used in a SW set-up uses bio-pellets which acts like a form of carbon dosing. This promotes the growth of the denitrifying bacteria which eats the nitrate and then is removed by the skimmer. That would not be very practical in a FW tank as there is no FW denitrifying bacteria like you find in SW

The closest thing that I have read about for fresh water is the use of a dual chambered media reactor passing the water down through media made up of sulfur balls then back up through crushed coral and back into the tank. From what I have read it works a lot like a calcium reactor and is very effective in removing nitrates in FW. But like I said, this is only based on what I have read as I have never tried a nitrate reactor in FW before. But this might be something worth looking into for your set-up.

[Taurus]

[Worried I'm missing something here ...


Nahhhh, you're just worrying to much. If the plants are using up the nitrates and phosphates in your tap water that quickly, then you have no problem. If this were my discus tank (which it is not) I would stick to regular water changes with tap water and think about adding some Seachem Purigen or PhosGuard.

Oh wait...you're plants need those to survive.

LOL...bottom line is stop worrying. When the discus look worried, then you should worry too and not before. :sconfused: